公开(公告)号：CA2422176C

公开(公告)日：2009-07-21

申请号：CA2422176

申请日：2003-03-14

Applicant: IBM CANADA

Inventor： ZHENG ROGER L Q ,  MCINNIS DALE M ,  WINER MICHAEL J ,  MCARTHUR CATHERINE S ,  HURAS MATTHEW A ,  GOSS JEFFREY J ,  ROMANUFA KERILEY K

IPC: G06F16/11

Abstract: A method and system for suspending log-based updating of a database in a manner that permits its resumption without restore, to permit efficient alternation between a log-based update mode and a database access mode. Unplayed log records are protected, as re versions of database pages at a time when the log-based update was suspended. This permits log-based updating to resume where it left off. In order to ensure consistent data for access, a roll-back procedure creates consistent data pagers that are us ed for access, and discarded when log-based update resumes.

公开(公告)号：CA2377649C

公开(公告)日：2009-02-03

申请号：CA2377649

申请日：2002-03-20

Applicant: IBM CANADA

Inventor： WILDING MARK F ,  HURAS MATTHEW A

IPC: G06F17/30 ,  G06F15/16

Abstract: A distributed database management system implemented on a cluster of computers. The cluster including disks organized as data nodes. The data nodes being locall y connected to one or more computers in the cluster. The distributed database management system includes a distributed database manager layer having a lock manager, a resource manager , and an architecture manager. The lock manager serializes access to the data nodes i n the cluster. The resource manager maintains a data representation of the resources of each computer in the cluster and makes the data available to other computers in the cluster to facilitate access to the resources by the other computers. The architecture manager defines logical ownership relationships between data nodes and computers in the cluster to permit the architecture o f the database to be dynamically reconfigured to provide improved performance.

公开(公告)号：CA2438366A1

公开(公告)日：2005-02-26

申请号：CA2438366

申请日：2003-08-26

Applicant: IBM CANADA

Inventor： ROMANUFA KERILEY K ,  SACHEDINA AAMER ,  HURAS MATTHEW A

IPC: G06F17/30 ,  H04L12/16

Abstract: For an information retrieval system coupled to a buffer pool maintaining a plurality of pages of recently accessed information for subsequent re-access , there is provided a method of starting the buffer pool. The method facilitates a quicker start to the buffer pool by deferring allocation of page storing portions, for example, until they ar e needed. The method comprises making the buffer pool available for storing pages while deferring allocation of a page storing portion of the buffer pool; and allocating the page storing portion of the buffer pool in response to a demand to store pages to the buffer pool . The method may be used to re-start a buffer pool with pages stored to a memory coupled to t he information retrieval system where the pages where stored upon a buffer pool shutdown. Further, buffer pool readers or prefetchers may be configured to read pages for storing to t he buffer pool and allocate the page storing portions of the buffer pool in response to instructions to read particular pages.

公开(公告)号：CA2422176A1

公开(公告)日：2004-09-14

申请号：CA2422176

申请日：2003-03-14

Applicant: IBM CANADA

Inventor： HURAS MATTHEW A ,  MCINNIS DALE M ,  WINER MICHAEL J ,  MCARTHUR CATHERINE S ,  GOSS JEFFREY J ,  ZHENG ROGER L Q ,  ROMANUFA KERILEY K

IPC: G06F16/11 ,  G06F17/30 ,  G06F17/40

Abstract: A method and system for suspending log-based updating of a database in a manner that permits its resumption without restore, to permit efficient alternation between a log-based update mode and a database access mode. Unplayed log records are protected, as re versions of database pages at a time when the log-based update was suspended. This permits log-based updating to resume where it left off. In order to ensure consistent data for access, a roll-back procedure creates consistent data pagers that are used for access, and discarded when log-based update resumes.

公开(公告)号：CA2422161A1

公开(公告)日：2004-09-14

申请号：CA2422161

申请日：2003-03-14

Applicant: IBM CANADA

Inventor： ROMANUFA KERILEY K ,  HURAS MATTHEW A ,  WINER MICHAEL J ,  FLASZA MIROSLAW A ,  BERKS ROBERT T ,  LAU LEO TAT MAN ,  SACHEDINA AAMER

IPC: G06F7/00 ,  G06F17/30

Abstract: The use of a centralized version table allows for efficient object switching. Rather than synchronizing all database agents to recognize a newly created file as containing the most recent version of a given object, database agents requiring access to the given object need only consult the centralized version table to learn file identity information. That is, the database agents consult the centralized version table to determine which of the files associated with a given object contain the most recent version of the given object. Mechanisms associated with the use of the centralized version table also provide for efficient recovery from a failure that has occurred during an object switching transaction.

公开(公告)号：CA2419883A1

公开(公告)日：2004-08-26

申请号：CA2419883

申请日：2003-02-26

Applicant: IBM CANADA

Inventor： OFER EFFI ,  WINER MICHAEL J ,  HURAS MATTHEW A ,  ZHENG ROGER L Q ,  MCINNIS DALE M

IPC: G06F17/30

Abstract: A system and method for selectively processing log files for enhancing performance of table space recovery by processing only those log files required, as well as choosing which log file to process during recovery for both redo and rollback phases of recover y. The system and method skips the processing of log files that do not contain records of interest for the table space being recovered and determines whether a log file contains anything that nee ds to be played, in particular for the recovery of a subsystem in the database, such as a table space. Pre processing of the log files is not done, rather including tablespace ID correlated with log file ID information is collected while the log files are created. The cross-correlated informati on is used during tablespace recovery to selectively determine which of the log files to process. Some log files may be skipped in cases where not all of the database system is being recovered. A sub set of the database can be recovered, such as a tablespace, and which log files to process is determined based on lock intent.

公开(公告)号：CA2353017C

公开(公告)日：2004-03-16

申请号：CA2353017

申请日：2001-07-12

Applicant: IBM CANADA

Inventor： SCHLAMB KELLY W ,  ZHENG ROGER L ,  HURAS MATTHEW A ,  LI JOHN ,  ROMANUFA KERILEY K ,  SACHEDINA AAMER

IPC: G06F3/06 ,  G06F11/14 ,  G06F11/20 ,  G06F17/30 ,  G11B27/10 ,  G11B25/04

Abstract: Writes to a disk by a set of application processes in a database management system are managed. The database management system provides data buffering, direct disk access and asynchronous tasks for managing the data buffering. Each application process seeking to write to the disk acquires a disk latch in SHARED mode before writing to the disk and releases the disk latch following completion of the write to the disk. A user process is able to suspend disk writes by issuing a pause command to asynchronous tasks and acquiring the disk latch i n EXCLUSIVE mode. The user process resumes disk writes by issuing a resume command to the asynchronous tasks and releasing the disk latch.

公开(公告)号：CA2383713A1

公开(公告)日：2003-10-26

申请号：CA2383713

申请日：2002-04-26

Applicant: IBM CANADA

Inventor： HURAS MATTHEW A ,  TREMAINE DAVID ,  BERKS ROBERT T ,  FLASZA MIROSLAW A ,  VALENTIN GARY ,  LAU LEO T M ,  MCARTHUR CATHERINE S ,  WINER MICHAEL J

IPC: G06F16/901 ,  G06F17/30 ,  G06F17/60

Abstract: The invention herein provides method and apparatus for managing attribute- tagged index entries contained in an index by assigning or tagging an index entry attribu te indicator to a newly inserted index entry (that is, at the time when a key data value is inserted into the index, the key data value becomes a newly inserted index entry and an attribute indicator i s tagged to the newly inserted index entry). The index entry can be placed anywhere within the index. Once a group of attribute-tagged index entries have been inserted into the index, the attribute identifiers can be switched off instantaneously (that is, the attribute associated with the attribute indicators is disabled). For example, an attribute identifier can be used to defer accessibility of appropriately attribute-tagged index entries until a predetermined time later when the attribute can be disabled and thus allow users to access the attribute-tagged index entries without having to remove the attribute indicators from the index).

公开(公告)号：CA2382718A1

公开(公告)日：2003-10-19

申请号：CA2382718

申请日：2002-04-12

Applicant: IBM CANADA

Inventor： BIRD PAUL M ,  VALENTIN GARY ,  HURAS MATTHEW A ,  XUE XUN

IPC: G06F9/50 ,  G06F12/00 ,  G06F12/02

Abstract: Memory balancing and optimization services (MBOS) control a size of a plurality of memory heaps, and a memory optimizer for allocating and de-allocating memory for a plurality of respective memory consumers. The MBOS may be instantiated within an application program such as a database management system providing services to memory consumers within the application. Alternatively, the MBOS may be instantiated within an operating system for providing services to memory consumers that are applications such as databas e management systems, e-commerce engines, operating systems, customer relationship management (CRM), enterprise resource planning (ERP), or supply chain management (SCM). Alternatively, an MBOS is instantiated within the operating system to provide services to applications and an MBOS is instantiated within each application to provide services to memory consumers within the application.

公开(公告)号：CA2374290A1

公开(公告)日：2003-09-01

申请号：CA2374290

申请日：2002-03-01

Applicant: IBM CANADA

Inventor： STOCKER RUSSELL M ,  HURAS MATTHEW A ,  LIMOGES JOSEPH SERGE ,  EVANS DOMINIQUE J

IPC: G06F9/00 ,  G06F9/46 ,  G06F13/00 ,  G06F15/16

Abstract: A spin counter updating system and method for updating spin counters for spi n latches in a multiprocessor computing system. The updating system includes main spin counter value storage for storing spin counter data correlated to at least one spin counter value, and a master agent. The master agent includes agent spin counter value storage for storing spin counter data correlated to at least one spin counter value; and a spin counter signal handler, wherein the spin counter signal handler is adapted to read spin counter data from the main spin counter valu e storage and to store the read spin counter data to the agent spin counter value storage.